Existing ventilation mask designs use a connection elbow or other rotating connections such as swivel adapters for attachment of a breathing circuit to the exterior of a ventilation mask. Attachment of connection elbows to a ventilation mask may be achieved by either snap connections or separate components such as snap rings. For example, existing ventilation masks may include connection elbows having tapered connections with a hub in the main body of the ventilation mask, where the connection elbow is inserted into the hub from outside the ventilation mask. Other existing ventilation masks may include connection elbows assembled from the outside of the ventilation mask by a C-clip attached inside the ventilation mask. Still further existing ventilation masks may include connection elbows assembled to the outside of the ventilation mask using snaps with or without push button releases.
However, if a large torque is applied to the connection elbows of the existing ventilation masks as described, the connection elbow may become disconnected from the ventilation mask and the connection between the breathing circuit and the ventilation mask may consequently fail, resulting in total loss of therapy. Also, as the air pressure inside the ventilation mask increases, the connection elbow can be pushed out from the ventilation mask, causing a small leak.
It would be desirable to provide a ventilation mask and an assembly method of a ventilation mask that would prevent disconnection between a breathing circuit and the ventilation mask, and that would prevent occurrence of small leaks from the ventilation mask at the elbow connection.